Question

When a concave mirror is placed facing the Sun, the Sun’s rays converge to a point
10 cm from the mirror. Now, if you place a 2 cm long candles flame 20 cm away on
the principal axis of the mirror, where would you place a screen to obtain the image
of the candle? What would see the size of the image? Draw a ray diagram to justify
your answer.

Answer 1

Hope this help you and diagram is found

Answer 2

The point where the concave mirror converges the rays is called focus.

According to question,
Focus is located 10cm away from mirror

So f = -10cm

Given,
Height of candle (h) = 2cm
Distance of candle from pole(u) = -20cm

According to mirror formula,

$\frac{1}{f}$=$\frac{1}{v}$ + $\frac{1}{u}$

$\frac{-1}{10}$ = $\frac{1}{v}$ + $\frac{-1}{20}$

$\frac{1}{v}$ = $\frac{-1}{10}$+$\frac{1}{20}$

$\frac{1}{v}$ = $\frac{-1}{20}$

So v = -20 cm

Now magnification = -v/u
So Magnification = 20/-20 = -1

So images it real, inverted, same size and formed at centre of curvation.

Screen should be placed at 20 cm away from mirror.